Although I can't speak to those specific statistics, as you can see from my copious disclaimers and leaving out entirely any information about edibility, I agree with the sentiments of this comment completely. Don't eat wild mushrooms unless you are 100% sure of the ID, and the safety of the land /growth medium, and are a professional or supported by professionals. Even then, professionals still make mistakes. Mushroom hunting for food is an inherently risky activity.
RE: The Amateur Mycologist #24 - Grifola frondosa - The Hen Of The Woods/The Maitake.